(a) Technical Field
The present invention relates to a method of estimating a junction temperature of a converter for a vehicle by applying a duty ratio in a different manner depending on a load region of the converter.
(b) Description of the Related Art
Generally, in eco-friendly vehicles, a converter serves to convert a voltage supplied from a high voltage battery into a low voltage. Therefore, the converter is applied with a high voltage, and load(s) are connected to various apparatuses, and as a result a considerable amount of heat is generated.
However, electric devices such as a diode and a capacitor that constitute the converter are vulnerable to high temperatures, and therefore the temperature of the converter has a great effect on durability and efficiency of the converter. Therefore, to increase the operational efficiency of the converter and improve the durability of the converter, it is important to appropriately maintain the temperature of the converter.
For this purpose, a method of determining a temperature of a converter and lowering the temperature of the converter based on the determined temperature is needed.
In connection with this, various control techniques of measuring temperature of a converter and cooling the converter based on the measured temperature have been proposed. Among those, a prior art proposes a method of calculating a temperature of a converter by measuring a temperature of air introduced into a power module and controlling the temperature of the converter using a cooling fan based on the calculated temperature.
However, the method of measuring the temperature of air introduced into the power module based on the prior art may indirectly estimate the temperature of the converter, and therefore it is difficult to accurately calculate the temperature of the converter. Further, when the existing cooling method uses a water cooling type, not an air cooling type, the existing measuring method may not be applied. In the case of using the water cooling type, the existing method has the problem in that the temperature of the converter may not be estimated.
The matters described as the related art have been provided only for assisting in the understanding for the background of the present invention and should not be considered as corresponding to the related art known to those skilled in the art.